The nohris peters co



(No Model.) 3 sheets-sheet 3.

` B. C. HBAVEY.

FURNAGB.

No. 585,572. Patented June 29,9189?.

, n.1' A l i Illliilll. gz

liee/22%?, fdernar Q eav A@ @www NiTnp STATES PATENT eric.

BERNARD O. IIEAVEY, OF'CHIOAGO, ILLINOIS, ASSIGNOR OF FORTY-NINE ONE-I-IUNDREDTHS TO SAMUEL T. THITE AND JOHN FLAIIERTY, OF

SAME PLACE.

F U R N AC E SPECIFICATION forming part of Letters Patent No. 585,572, dated June 29, 1897.

Application filed October 5, 1896. Serial No. 607,916. (No model.)

` To all whom, t may concern:

Be it known that I, BERNARD C. I-IEAVEY, a citizen of the United States, residing at Ohicago, in the county of Oook and State of Illinois,have invented a new and useful Improvement in Furnaces, of which the following is a specification.

My invention relates to improvements in furnaces for use more especially in burning fuel-dust.

My objects are to provide certain improvements in the construction of the interior or nre-chamber portion of the furnace, and also improved means for automatically feeding the dust to thefurnace, all to the end of economizing in the use of the fuel-dust and of producing approximately perfect combustion of the inflammable portions thereof.

In the drawings, Figure l is a broken vertical longitudinal section taken on line l of Fig. 4 and showing my improvements applied to a boiler-furnace; Figs. 2 and 3, sections taken on lines 2 and 8, respectively, of Fig. l; Fig. 4, a broken plan section taken on line 4 of Fig. 1, and Fig. 5 a broken and sectional elevation of automatic feeding means for the fuel-dust.

A is the front wall of the furnace; B and B', the side walls; O, a forward top wall; D, the bridge-wall E, the combustion-chamber, and F the ash-pit. Extending through the wall A,near the base of the combustion-chamber, is an opening t, provided with a hinged door s. In the. wall A and vextending from the top thereof to the opening t is a fuelchute fr. The forward portion of the combustion-chamber E consists of an opening or passage E at its front end approximately of the size of and registering with the door-opening t and iiaring thence upward and laterally, as indicated, and an enlarged chamber portion E2, having inclined sides and closed at the top by the boiler X. The sides of the passage E and chamber E2 are formed of slabs or blocks p of fire-clay, having their inner faces formed with upward and downward extending corrugations. The top of the flaring passage E is arched and formed of blocks p' of nre-clay, presenting on their inner surfaces longitudinally-extending corrugations. The object of the corrugations is to present an increased radiating-surface, the construction shown affording about double vthe surface which would be presented 4`m m may be provided at their outer ends with suitable dampers m2 for the regulation of the volume of air passing through them.

The grate G, as I prefer to provide it, consists of the closely adjacent parallel and longitudinallyextending metal bars l, resting at the center upon a transverse supporting-bar Z and at opposite ends upon sills Z2 on the furnace-walls.

G is a series of supplemental grate-bars formed, preferably, of hre-clay or the like refractory material, tapering along their upper sides, provided on their under sides with shoulders which rest upon adjacent barsZ, and having downwardlyextending lugs which iit between adjacent bars l. The supplemental grate-bars thus' close every second opening between bars Z and shield said bars from the direct action of the flames in the combustion-chamber. The bridge-wall D is provided with an inclined face 7c at the rear end of the grate G', whereby in scraping out ashes the scraper inserted through the dooropening t may be drawn down the surface k and readily engage ashes deposited at the rear end of the grate.

Formed, preferably, integral with the door s is a shelf s, extending from the center of the door backward to a point beyond the lower end of the chute r.

H is a blast-pipe extending, preferably, Jthrough an opening in the door s in ahori- Zontal direction above the shelf s'. Interposed in the pipe II is a valve II.

My improved furnace, constructed as described, is intended more especially for use in burning coal-dust, and particularly the dust which accumulates at themines and has hitherto been considered worthless for fuel.

In operation the dust is fed by gravity through the chute 9" and falls toward or upon the shelf s. I prefer in practice to connect the pipe II with a steam-supply under a pressure which will cause the dust as it falls toward the shelf to be caught by the steam current and sprayed backward throughout the combustion-chamber. An air-blast may be employed, if desired, but, owing to the hydrogen furnished by the steam, a very intense heat is generated. Originally a lumpooal fire maybe built upon the grate and when the bed is sufficiently incandescent the coal-dust may be sprayed into the combustion-chamber, as described. Part of the air to support combustion maybe caused to enter through the door F of the ash-pit, which door I providewith'a suitable damper F2. This air passes from the ash-pit upward between the grate-bars. Additional air-currents to support combustion enter through the passages m m/ at opposite sides of the passage E', and these air-currents maybe controlled by means of the dampers m2. In practice when the fire is well started the incoming -coal-dust becomes ignited in the chamber or n a measure retard the passage of the products of combustion from the combustion-chamber in order to conline them in the latter for a sufficient time to produce approximately ab solute combustion, and as a means for accomplishing this purpose I provide upon the bridge-wall D vertical fingers i, preferably of fire-clay and set equid-istant apart to afford a vertical bridge-wall grate D', as shown. The fingers i are preferably beveled at the top at opposite sides and extend close to or contact with the under surface of the boiler X. I have found in practice that my improved furnace constructed as described has a very much greater steam-producing capacity than furnaces of the same size burning the same quantity of expensive lump coal and that the furnace is practically smokeless. The large radiatingsurface in the combustion-chamber, effected by the corrugations and the fact of confining the heat by means of the casing n, contributes largely toward the effectiveness of the furnace as a steamproducer, land I have found that even after shutting off the supply of fuel toward the end of a days work the heat stored in the walls of the combustion-chamber will continue the production of steam in the boiler X for several hours. Vhile the supplemental grate-bars G are not indispensable, they in themselves form a desirable heat-storage medium, and by protecting the metal bars Z ot' the grate Gr render the latter practically indestructible.

To obtain the best work from the furnace, so that it will `generate the desired amount of heat,neither more norless, and emit no smoke, it is desirable to provide mechanical means for feeding the coal-dust automatically and continuously in properquantities. The mech anism shown in Fig. 5 is adapted for feeding two adjacent furnaces, though it may be provided for a single furnace or extended to accommodate more than two. It consists of a bin or receptacle I, placed, for convenience, upon the iioor at one side of the furnace and provided in its top at one side with a door h, through which the fuel-dust may be shoveled or otherwise fed. Extending upward from the top of the bin I is a pipe or chute I', terminating at its upper end in a hopper-shaped compartment I2. Centrally within the pipe I is a tube I3, which extends upward from near the lower end of the receptacle I and carries at its upper end a hopper-shaped receptacle I4. In the tube I3 is a screw conveyer I5, which extends from the bottom of the receptacle I to a point above the top of the tube I3.. The hopper I4 terminates in a plane below the top of the hopper I2, and the parts are so constructed that a space h exists all around the hopper I4 and tube I3. At the upper end of the screw conveyer I5 is a pulley h2, which may be belted to a suitable drive-pulley, whereby the screw conveyer is rotated.

Fuel-dust deposited in the receptacle I will be raised by the screw conveyer through the tube I8 and deposited in the hopper I4. In the event that the dust is carried to the hopper I4 faster than it is taken away, as hereinafter described, the dust will overflow and drop through the space 7L back to the receptacle I. Extending from the hopper I4 horizontally across the front of the furnace or furnaces is a conveyer-tube I6, containing a conveyer-screw I7, which extends from the lower end portion of the hopper practically throughout the tube I6. The screw is provided with a pulley h3, which may be connected by a belt to a suitable dri vepulley to turn the screw at the desired speed. In front of each furnace is a hopper or distributing-receptacle I8 below an opening 71.4 in the conveyer-tube IG. At the end of the tube I( is a chute I9, which terminates at its lower end in a close receptacle Ilo, provided at one side near the bottom with an opening having a door h5. The screw conveyer I7 carries the dust from the hopper I4 to the first hopper I8, and when the latter is filled it carries the dust to the second hopper IS, and so on. When all the hoppers I8 are filled, the coal-dust conveyed by the screw I7 falls through the chute I9 to the overflow receptacle 140, whence it may be withdrawn from time to time, as desired, and shoveled or otherwise conveyed back into the IOC) IIC

receptacle 1. Extending from the lower end of the hopper 11s to the feed-chute r of the furnace is a conveyer-tube 111, containing a screw couveyer112, provided with a pulley 113, which may be belted to a drive-pulley. The screw 112 terminates at a compartment r at the upper end of the chute r, and between said compartment and chute is a screen r2. On the shaft of the screw 112 in the compartment r are agitators which may be in the form of ngers h6, which in the rotation of theshaft stir up the dust and clean the screen r2, so that an even flow of more or less pulverulent fuel will occur through the chute 9^. The pulleys 113 may be step-pulleys, as shown, so that the speed of the conveyer-screws 112 may be quicklyand easily regulated to supply the desired amount of fuel-dust to the chutes fr.

All the improvements shown and described contribute to the result of effecting economy in the use of the fuel and obtaining the greatest possible steam production therefrom. By regulating the speed, particularly of the conveyer-screw 112, just the desired amount of fuel-dust will be carried to and sprayed into the furnace and the combustion-chamber will never become cloggedor overfed. By regulating the supply of air which enters through the openings m m a sufficient amount of oxygen may be provided to support combustion without producing any material cooling effect in the combustion-chamber.

The'construction of the combustion-chamber gives it great capacity for heat storage and radiation, assists greatly in raising the fuel as it is sprayed into the chamber quickly to the incandescent point, and, owing to the intensity of the heat, it prevents the formation of slag on the grate-bars when the coaldust contains impurities. The corrugated sides of the chamber aid materially in deflecting the currents which strike them, and

by the stirring up of the products of combustion thus effected more perfect combustion is produced. The beveled tops of the fingers which form. the grate-section D' enlarge the outlet at the top and therefore close to the surface of the boiler, besides preventing the accumulation of ashes at the tops.

1n practice a much smaller combustionchamber in comparison to the size of the boiler may be employed than is necessary where lump coal is used as the fuel, owing to the fact that the construction tends to conne and intensify the heat. 1n the use of coaldust of average purity comparatively little of the solid products of combustion pass beyond the bridge-wall, so that the boiler-fines need be cleaned much less frequently than is ordinarily required and no appreciable smoke issues from the chimney. Owing to the fact that approximately all of the inflammable portion of the fuel is consumed in the combustion-chamber only a dry pulverulent ash is deposited upon the grate. This ash falls readily between the grate-bars, and as a consequence comparatively little stoking or iscraping is required. Vhen the fuel employed is comparatively free from refractory impurities, stokin g and scraping of the gratebars is necessary only at long intervals, if at all. Vhen it is desired to stoke the fuel or scrape the grate-bars, the doors, carrying the steam-pipe 111, may be readily opened and the work quickly performed. 1t is desirable to provide belt-shipping mechanism to stop the action of the screw conveyers whenever the door s is opened. By tightly closing all doors and the dampers m2 the stored heat may be employed for steam production after stopping the feeding of the fuel-dust and steam, and the attendant may in practice close down the furnace some time before the end of the days work and still have an ample supply of steam to the end of the time required.

While 1 prefer to construct my improvements throughout as shown and described, they may be lnodified in the matter of details of construction withoutdeparting from the spirit of my invention as defined by. the claims.

What 1 claim as new, and desire to secure by Letters Patent, is

1. 1n a fuel-dust furnace, the combination with the combustion-chamber, and means at one side thereof for spraying the fuel-dust into the chamber comprising a fluid blastpipe and fuel feed-chute just in advance of said pipe, of automatic supplying means for the chute comprising a storage-receptacle, a compartment at the upper end of the chute, a screen between the compartment and chute, a fuel-advancing conveyer extending from said receptacle to the compartment, and agitator mechanism in the compartment, substantially as and for the purpose set forth.

2. 1n a fuel-dust furnace, the combination of a combustion-chamber comprising a gradually enlarging passage E and enlarged chamber portion E2 having corrugated side walls of {ire-clay and an outlet, a grate below the chamber, an air-inlet at the said passage, additional air-inlets at opposite sides of the chamber, a fuel feed-chute toward the outer end of the passage, and a fluid blast-pipe opening into the outer end of the passage just beyond the feed-chute, all constructed and arranged to operate substantially as and for the purpose set forth.

3. 1n a fuel-dust furnace, a combustionehamber comprising a passage E having side walls provided with up-and-down corrugations, and an arched top provided with longitudinal corrugations, and an enlarged cham-j,

ber portion E2 having vertically-corrugated side Walls, in combination with a fuel feedchute toward the outer end of said passage and a fluid blast-pipe opening into the outer end of said passage just beyond the feedchute, substantially as and for the purpose set forth.

4. 1n a fuel-dust boiler-furnace, the combination of a combustion-chamber, a bridgewall at the rear end of said chamber, a ver- ICO IIL)

tically-disposed grate upon the bridge-Wall comprising` parallel vertically-disposed iingers beveled at their upper ends, a fuel feedchute at the forward end portion of the chamber and a fluid blast-pipe opening,` into the chamber just beyond the said chute, all constructed and arranged to operate substantially as and for the purpose set forth.

5. In a fuel-dust boiler-furnace, a combustion-chamber provided with side Walls having up-'and-down corrugations and com prisin g an enlarged chamber portion E2 and reduced and arched passage portion E', a grate G comprising parallel longitudinally-extending metal bars Z, a supplemental grate G comprising fire-clay bars resting upon and shielding the bars l, in combination With a fuel feedchute toward the outer end of said passage and a fluid blast-pipe opening into the outer end of said passage just beyond the feedchute, substantially as and for the purpose set forth.

6. In a fuel-dust furnace, the combination of a combustion-chainber Comprising,` the enlarged chamber portion E2 and reduced passage portion E provided with a door-opening` t, a door s at said opening, a shelf s on the door, a fluid blast-pipe H extending through said door above the said shelf, a fuel feedchute in the front Wall of the furnace terminating above the shelf and back of the said pipe, and fuel-dust-supplying means for said feed-chute, su bstantially as and for the purpose set forth.

7. A fuel-dust feeder for furnaces, comprisin g, in combination, a su pply-bin for the dust, an overfloW-receptacla'a dust-conveyer extending-'from said bin to the overflow-receptacle, a distributi 11g-receptacle in the line of said eonveyer, and a dust-conveyer extending from the distributing-.receptacle t0 the furnace, substantially as and for the purpose set forth.

BERNARD C. HEAVEY.

In presence 'of- J. H. LEE, M. J. FROST. 

